A capacitive touch screen allows a user to interact with an electronic device without using a mouse or track pad. When an object (e.g., a user's finger or a stylus) touches or comes within proximity of the surface of a capacitive touch screen, a change in capacitance occurs within the touchscreen at the location of the touch or proximity. A touch-sensor controller processes the change in capacitance to determine whether an object is touching or in proximity to the touch sensor or to determine the location of the touch or proximity with respect to the touch sensor.